Global warming is the unusually rapid increase in Earth’s average surface temperature over the past century primarily due to the greenhouse gases released as people burn fossil fuels. Despite ups and downs from year to year, global average surface temperature is rising.

Data from the US National Oceanic and Atmospheric Administration (NOAA) shows that the average global sea surface temperature – the temperature of the upper few metres of the ocean – has increased by approximately 0.13°C per decade over the past 100 years.

Over the last century, the average surface temperature of the Earth has increased by about 1.0o F. The eleven warmest years this century have all occurred since 1980, with 1995 the warmest on record. A warmer Earth speeds up the global water cycle: the exchange of water among the oceans, atmosphere, and land.

According to NOAA’s 2020 Annual Climate Report the combined land and ocean temperature has increased at an average rate of 0.13 degrees Fahrenheit ( 0.08 degrees Celsius) per decade since 1880; however, the average rate of increase since 1981 (0.18°C / 0.32°F) has been more than twice that rate.

NOAA scientists used much of the same raw temperature data, but with a different interpolation into the Earth’s poles and other data-poor regions. NOAA’s analysis found 2019’s average global temperature was 1.7 degrees Fahrenheit (0.95 degrees Celsius) above the 20th century average.

2020

One reason for the hotter weather, the experts said, is because of an incoming La Niña, which is a “periodic cooling of water in the eastern equatorial Pacific Ocean” that influences weather patterns near the U.S. and beyond throughout the year.

At least five major ice ages have occurred throughout Earth’s history: the earliest was over 2 billion years ago, and the most recent one began approximately 3 million years ago and continues today (yes, we live in an ice age!). Currently, we are in a warm interglacial that began about 11,000 years ago.